Microbiological Samples Research Articles

Microbiological findings in acohort of patients with coronavirus disease 2019 and venovenous extracorporeal membrane oxygenation.

Venovenous extracorporeal membrane oxygenation (VV ECMO) is an established support option for patients with very severe respiratory failure and played an important role during the coronavirus disease 2019 (COVID-19) pandemic. Bacteria and fungi can lead to severe infectious complications in critically ill patients. The aim of this study was to describe the microbiological spectrum of bacteria and fungi detected in patients with COVID-19-associated respiratory failure supported with VV ECMO in our center. This retrospective single-center analysis included all patients with COVID-19-associated respiratory failure supported with VV ECMO in our center between March 2020 and May 2022. All findings from microbiological samples, taken as part of clinical routine assessment from initiation of VV ECMO until day30 were included. Samples were described by site and time of detection and microbiological characteristics. From March 2020 through May2022, 88patients with COVID-19-associated respiratory failure received VV ECMO support at our center. In 83/88 patients (94.3%), one or more pathogens were found in microbiological samples. Most pathogens were isolated from samples from the respiratory tract (88.6%). Earliest detection occurred in samples from the respiratory tract with amedian time of 5days to first detection. The most frequently detected pathogens were Staphylococcus spp., Candida spp., Klebsiella spp., Escherichia coli and Enterococcus spp. In this cohort of severely ill COVID-19 patients receiving VV ECMO support, pathogens were frequently detected.

Lung Ultrasound-A Supplementary Tool for the Diagnosis of Pulmonary Tuberculosis in Children.

There are logistic problems in obtaining adequate microbiological samples for the diagnosis of pulmonary tuberculosis (PTB) in children, globally. Most studies on ultrasound have evaluated mediastinal nodes in children with tuberculosis (TB), but very few studies are available on lung ultrasound (LUS) appearances in proven PTB. To study the LUS appearances in children with microbiologically proven PTB and to assess the inter-observer agreement. Thirty children with microbiologically proven PTB, were evaluated prospectively on LUS and chest radiograph (CR) in Radiology department of a tertiary care hospital, from November 2019 to November 2021. CR was interpreted by an experienced Radiologist (R2); LUS was conducted by a Radiology resident (R1), who was blinded to CR findings; and findings were recorded. Archived static images/videos of LUS were interpreted by R2 after a month, to avoid bias; and findings were recorded. Composite LUS finding of either consolidation and subpleural nodule (SUN) was detected in 29/30 (96.7%) children with lower zone predominance (70%). Miliary pattern was observed on LUS in 11/30 (33.3%) children, but their CR was normal. Consolidation was detected on LUS in a significantly higher proportion of children (83.3%) than on CR (43.3%). Inter-observer agreement calculated for detection of consolidation and pleural effusion was k = 0.88, for B lines k = 0.79, confluent B lines k = 0.75, miliary nodules k = 0.70 and SUN k = 0.57. We conclude that in low-resource endemic areas, LUS by virtue of being non -invasive and not using ionizing radiation, can be a useful supplementary tool in the diagnosis of childhood PTB.

P-2305. Study of Prescribing patterns and Effectiveness of Ceftolozane/Tazobactam [C/T] Real-world Analysis Results (SPECTRA): Results of the Immunocompromised Patients

Abstract Background This sub-analysis of the SPECTRA (Study of Prescribing patterns and Effectiveness of Ceftolozane/Tazobactam [C/T] Real-world Analysis) study aimed to describe the clinical characteristics, treatment patterns, and outcomes of hospitalized adult immunocompromised patients.Table 1. Patient characteristics and Microbiology‡ For patients aged 90 or older the HCP was asked not to enter the exact age and to check a specific box. Therefore, patients aged 90 or older are included in 'Missing' and are not considered in the calculation of mean, median, etc. immunocompromised did not include chronic steroid use, age, or diabetes. Positive culture for more than one organism may apply for one patient. Missing data correspond to patients with no microbiological (MB) sample for index infection, that is without any MB sample performed within +/- 14 days around the index infection with a positive culture result and at least one GN antibacterial tested (whatever the susceptibility result is). Methods SPECTRA was a multicenter observational study conducted in 7 countries, with patients (age≥18yrs) who received ≥48-hours C/T treatment (n=617). Medical records were extracted covering a 6-month period prior to the index date, up to 30 days after the last dose of C/T or until death. All-cause in-hospital mortality (ACHM), clinical success, ICU admission, microbiology results, and treatment patterns in immunocompromised patients (IP, n=268) are reported. Immunocompromised patients were defined as patients with a Hematologic Malignancy or Solid Tumor or recipient of transplant. Transplant patients (TP) was 60% (n=160).Table 2. Clinical Outcomes: All-Cause In-Hospital Mortality and Clinical Success*Bile duct anostomic leakage, CMV infection, Post-operative Complication, Digestive hemorrhage, Invasive fungal infection, C difficile colitis(1) More than one criterion may apply for one patient. Results Median age was 57 (IP) and 50.5 years (TP). 66% and 67.5% were male, respectively.28.4% had respiratory-related infections (RRI), 22.7% had sepsis, 27.6% had septic shock, 13.4% had Cystic Fibrosis, 29.4% had pneumonia, 2.6% had bone and joint infection. ACHM was 24% for IP, and 23% for TP. Time from index date to death was a median of 29 and 35, respectively. Leading causes of death were sepsis (31%), multiorgan failure (29%), cancer (12%) for IP. Clinical success was 62.7% for IP. 84% (143/170) were Pseudomonas aeruginosa (PsA), and MDR PsA was 71.8% (n=122). 38.7% (n=98) received optimal dose. Up to 50% of the patients were admitted to ICU during the index hospitalization (n=133), and 46% of the ICU admissions were related to index infection. Median length of stay at ICU was 13 days.Table 3.Treatment patterns and Intensive Care Unit (ICU) Conclusion Treatment with C/T resulted in a high rate of clinical success in this real-world cohort of immunosuppressed patients, despite dosing that frequently deviated from labelled dosing. Pseudomonas aeruginosa including MDR isolates were frequently identified. Based on these results C/T is a useful option for the treatment of GN infections including those due to MDR PsA in the immunosuppressed patient population. Disclosures Emre Yucel, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) David Paterson, bioMerieux: Grant/Research Support|bioMerieux: Honoraria|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pfizer: Honoraria|Shionogi: Grant/Research Support|Shionogi: Honoraria Florian Thalhammer, MD, MSD: Advisor/Consultant Stefan Kluge, Prof. Dr. med., Merck & Co: Advisor/Consultant|Merck & Co: Board Member Mike Allen, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) Brune Akrich, MD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) Yanbing Zhou, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company)

P-244. Antibiotic Prescribing Patterns in Ventilator Associated Pneumonia and their Effect on Carbapenem Resistant Organism Colonisation in Asian Hospitals

Abstract Background Ventilator-associated pneumonia (VAP) is associated with prolonged hospitalisation, excessive antibiotic use and high mortality. Antibiotic regimens used for VAP and their effect on development of carbapenem resistant (CR) organisms (CRO) have not been well characterised, especially in Asia.Table 1.Antibiotics used for index episode of VAP caused by carbapenem resistant organisms, and overall carbapenem use Methods The REGARD-VAP study was a randomised trial conducted in 39 intensive care units in Nepal, Singapore and Thailand. Adults aged ≥18 years with VAP (defined by the US CDC and Prevention National Healthcare Safety Network criteria), who had been mechanically ventilated for ≥48 hours, and received culture-directed antibiotics were enrolled. In culture-negative cases, antibiotics were prescribed as per local hospital antibiograms. We analysed the antibiotics prescribed in VAP and their association with CRO acquisition. We also assessed the effect of CRO colonisation on 60-day mortality and VAP recurrence.Table 2.Factors associated with new carbapenem-resistant organism (CRO) isolation in microbiological samples in a multivariable logistic regression model Carbapenem use for index episode of VAP was independently associated with higher odds ratio of new CRO colonization when adjusted for duration of antibiotics, and length of hospital stay. Duration of ICU stay was not included in this model due to high collinearity with length of hospital stay. Results The study enrolled 460 participants and the majority (47.4%) of VAP was caused by Gram-negative non-fermenters (VAPnf). Amongst participants with CR VAPnf, 56 (45.5%) received colistin-based regimens and 48 (39.0%) received beta-lactams. Amongst those with CR Enterobacterales, 11 (44.0%) received either a colistin-based regimen or beta-lactams. 52 different antibiotic regimens were used to treat CR VAP, and only one participant received a novel beta-lactam/beta-lactamase inhibitor (Ceftazidime-avibactam). 45.9% of all antibiotic regimens included carbapenems which was independently associated with new acquisition of CRO during the study period (OR 1.80, 95% CI 1.10 – 2.93, p=0.019). In a Cox regression model, CRO colonization (n=176, 38.3%) was associated with higher 60-day mortality (HR 1.66 (95%CI 1.21 – 2.28), p=0.002) and VAP recurrence (HR 8.37 (95% CI 4.28 – 16.38), p< 0.001) when adjusted for demographic factors, disease severity, comorbidities, antibiotic duration, and VAPnf.Figure 1.Cox-Regression Survival analysis showing 60-day mortality (left) and 60-day VAP recurrence (right) in participants with or without Carbapenem Resistant Organism (CRO) colonization. 60-day mortality and VAP recurrence was adjusted for demographic factors (patient age and gender), disease severity (qSOFA score and inotropic requirement at VAP diagnosis), comorbidities (Charlson comorbidity index and presence of congestive cardiac failure, acute coronary syndrome, chronic obstructive pulmonary disease, chronic kidney disease, cirrhosis, cancer, diabetes), duration of antibiotics prescribed for index episode of VAP, use of appropriate empiric antibiotics to which the organism was susceptible prior to switching to culture-directed antibiotics and cause of VAP (presence/ absence of Gram-negative non-fermenter). Participants with CRO colonization had increased hazards ratio of mortality and VAP recurrence. Conclusion In lower, middle- and high-income countries in Asia, variable antibiotic regimens were used for the treatment of VAP, majority consisting of colistin and carbapenem based regimens, with the latter being associated with higher rates of new CRO isolation. There is a need for better treatment options for these difficult to treat pathogens across the income spectrum in Asia. Disclosures Paul Tambyah, MBBS (S'pore), Diplomate, American Board of Internal Medicine and Infectious Diseases, Moderna: Grant/Research Support|Sanofi-Pasteur: Grant/Research Support

Integrated Analysis of Indoor Air Quality and Fungal Microbiota in Educational Heritage Buildings: Implications for Health and Sustainability

Indoor air quality is paramount for the health and well-being of individuals, especially in enclosed spaces like office buildings, schools, hospitals, and homes where people spend a significant amount of time. Ensuring good indoor air quality is not only essential for reducing symptoms such as headaches, eye and respiratory irritation, fatigue, and difficulty in concentration, but it is also a key component of sustainable building practices aimed at promoting long-term health and environmental balance. This study aims to explore the impact of the microclimate and fungal microbiota on the health and cognitive performance of occupants in a university classroom, which is part of a cultural heritage building. The research delves into various microclimatic parameters, including temperature, relative humidity, CO2, volatile organic compounds, O2, and particulate matters (PM2.5 and PM10), to understand their influence on the development of microbiota and the manifestation of symptoms associated with Sick Building Syndrome. Over the course of a year-long investigation, microbiological samples were collected, revealing the presence of 19 fungal species, with Cladosporium, Alternaria, and Aureobasidium being the most prevalent genera. These species were found to thrive in an environment characterized by inadequate ventilation, posing potential health risks to occupants, such as allergic reactions and respiratory infections. Microclimatic parameter values such as mean temperature of 22.9 °C and mean relative humidity of 38.5% indicated moderate conditions for fungal proliferation, but occasional high levels of PM2.5 and CO2 indicated periods of poor indoor air quality, negatively influencing the comfort and health of the occupants. The questionnaires completed by 190 students showed that 51.5% reported headaches, 44.2% frequent sneezing, and 43.7% severe fatigue, linking these symptoms to increased levels of CO2 and PM2.5. The novelty of the study lies in the integrated approach to indoor air quality assessment in a heritage educational building, highlighting the need for improved ventilation and air management to enhance health and cognitive performance, while emphasizing sustainable indoor environment management that balances occupant well-being with the preservation of cultural heritage.

P-373. The VREy Resistant Enterococcus: Retracing VRE Transmission and Contamination Events in Healthcare Settings

Abstract Background Healthcare associated infections (HAIs), particularly those involving antibiotic resistant bacteria, are some of the most common, deadly, and preventable adverse events affecting patients in the clinical setting. Lowering HAI transmission rates would reduce the clinical burden to patients, economic burden to healthcare systems, and could help slow an alarming trend toward antimicrobial resistant organisms. However, determining definitive routes of transmission within healthcare facilities (HCFs) of HAIs is difficult and costly. Since HAIs are common in settings with little direct patient-patient contact, discerning the role of fomites in transmission pathways is critical, either via health care workers (HCWs) or from direct patient contact with contaminated surfaces. Methods We present preliminary results of a model of who-infected-whom using densely sampled data from ICU units in two HCFs over 13 weeks. We combine daily microbiologic samples from three patient body sites, HCW hands, three zones within patient room environments, and shared environmental surfaces with epidemiologic data on HCW movement. Microbiologic samples were whole genome sequenced (WGS) for all distinct cultures. We developed a Bayesian transmission model that incorporates genomic and epidemiologic information to reconstruct probabilistic estimates of transmission routes to estimate who-infected-whom and rule out unlikely transmission or contamination events. Results This poster focuses on results for the vancomycin-resistant enterococci (VRE) samples (N=44). We characterize the relationship between overlapping and non-overlapping patient stays, HCW hands, and environmental surfaces, and their roles in transmission and contamination within the two HCFs. Conclusion Ultimately, these results provide further evidence on pathogen movement in HCFs and provide insights for developing and improving interventions to minimize transmission in HCFs. Disclosures All Authors: No reported disclosures

P-1113. Treatment Patterns and Clinical Outcomes in Hospitalized Patients with Febrile Neutropenia treated with Ceftolozane/Tazobactam: A Subgroup Analysis of the SPECTRA study

Abstract Background This sub-group analysis of the Study of Prescribing Patterns and Effectiveness of Ceftolozane/Tazobactam(C/T) Real-world Analysis (SPECTRA) described treatment patterns and outcomes in hospitalized patients with Febrile Neutropenia (FN).Table 1.Treatment patterns of Febrile Neutropenia by C/T and C/T Treatment duration and All-Cause In-Hospital Mortality (ACHM)Abbreviations: CRI= Chronic Respiratory Infection cIAI= Complicated Intra-abdominal Infection cUTI= Complicated Urinary Tract Infection (1) For patients aged 90 or older the HCP was asked not to enter the exact age and to check a specific box. Therefore, patients aged 90 or older are included in 'Missing' and are not taken into account in the calculation of mean, median, etc. (2) Several indications may have been reported for the same patient. (3) A patient is counted once for each single indication or combination of indications. Methods SPECTRA was a multicenter, observational study, in hospitalized adult patients treated with C/T for ≥48 hours in 7 countries (n=617). Medical records were extracted, covering 6 months prior to the index date, up to 30 days after the last dose of C/T or until death. Descriptive statistics were reported here on treatment patterns, all-cause in-hospital mortality (ACHM), clinical success and microbiologic response in cases of Febrile Neutropenia (FN, n=38).Table 2.Clinical Success, Microbiologic Response, and Duration of GN antibacterial therapy (days) between Neutropenic and non-Neutropenic patients1Analysis includes only those with known status for clinical success, and only those with known status for microbiological response. Responses of 'Unknown' are considered as missing data. Microbiological response was defined as negative culture result at site of index infection with same organism post C/T administration. Results The median duration of C/T treatment was 8 days, median time from index hospitalization admission to C/T initiation was 18 days, and from the first microbiological sample to C/T initiation 3.5 days (Table 1). ACHM was 9.2% (n=12). Clinical success was 69.4% (n=25) (Table 2). 63% of the patients (n=24) received suboptimal doses for treatment. MDR Pseudomonas aeruginosa and, ESBL-producing Enterobacterales were isolated in 15 and 4 patients, respectively. One had a clinical diagnosis of both pneumonia and sepsis, 2 patients with pneumonia, 4 with respiratory related infections, 1 with skin infection, 3 with sepsis, 1 with cIAI, and 2 with cUTI, in addition to FN. Microbiologic response was achieved for 30.6% of the patients, who received a median of 17 days of GN antibacterial therapy.Table 3Appropriate* Dose of C/T by Indication for Index Event*If the dose received was different (lower or higher) from the appropriate dose as defined, then the patient was considered as not having received the appropriate dose. If the dose received was different (lower or higher) from the appropriate dose on the first day but was then adjusted to the appropriate dose, then the patient was considered as having received the appropriate dose. For patients having both respiratory and non-respiratory infection, the appropriate dose for respiratory infection (=the highest dose) was considered as the appropriate dose for the patient. Conclusion These findings demonstrate potential new findings for the treatment of febrile neutropenia. However, further research is needed to explore its full potential and optimize dosing strategies for improved outcomes. Disclosures Yanbing Zhou, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) David Paterson, bioMerieux: Grant/Research Support|bioMerieux: Honoraria|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pfizer: Honoraria|Shionogi: Grant/Research Support|Shionogi: Honoraria Florian Thalhammer, MD, MSD: Advisor/Consultant Stefan Kluge, Prof. Dr. med., Merck & Co: Advisor/Consultant|Merck & Co: Board Member Mike Allen, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) Brune Akrich, MD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) Emre Yucel, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company)

P-1076. Describing the clinical characteristics, treatment patterns, and outcomes in hospitalized pneumonia patients treated with Ceftolozane/Tazobactam (C/T): Insights from the SPECTRA Study

Abstract Background This sub-analysis of the SPECTRA (Study of Prescribing patterns and Effectiveness of Ceftolozane/Tazobactam [C/T] Real-world Analysis) study aimed to describe the clinical characteristics, treatment patterns, and outcomes of hospitalized pneumonia patients treated with ceftolozane/tazobactam (C/T).Table 1.Patient characteristics and Microbiology2 Immunocompromised defined as: ‘Immunocompromised present’ [raw item] or ‘Hematologic Malignancy present’ or ‘Solid Tumor present’ or ‘Transplant=Yes’. Methods SPECTRA was a multicenter observational study conducted in 7 countries. It included adult patients (age≥18yrs) who received ≥48-hours C/T treatment (n=617). Retrospective data were extracted from medical records covering a 6-month period prior to the index date, up to 30 days after the last dose of C/T or until death. Descriptive statistics were used to analyze clinical success, all-cause in-hospital mortality (ACHM), intensive care unit (ICU) admission, length of stay (LOS) in the subcategory of pneumonia (n=182).Table 2.Outcomes with Ceftolozane/tazobactam and Treatment duration (days) (Treatment interruptions not included)*Other conditions: Bile duct anostomic leakage, Brain-vascular hemorrhagic accident, CMV infection, Encephalic Death, Hemorrhage, Invasive fungal infection, Necrotizing pancreatitis, Post operative complication, Renal amyloidosis, Spontaneous rupture of the spleen, Septic shock, Hemodynamic dysfunction, Kidney failure, Stable angina grade I-II CCS, Probable Clostridium difficile colitis, Progression of AML, Refractory Hypoxemia, Refractory hematologic malignancy, Subarachnoid Hemorrhage, Solid tumor, Tracheobronchitis Results The median duration of C/T treatment was 11.0 days, median time from index hospitalization admission to C/T initiation was 19.0 days, and from the first microbiological sample to C/T initiation 6.0 days. All-cause in-hospital mortality was 32.4% (n=59), with a median time from the index to death of 28.0 days. The causes of death included sepsis (38.9%) and pneumonia (18.6%) and 67% (n=122) patients were admitted to the ICU during the index hospitalization. Pseudomonas aeruginosa (PSA) was the most commonly isolated pathogen (88% of patients), with MDR PsA present in 68.4% (n=80) of pneumonia patients. Conclusion In hospitalized patients with pneumonia treated with C/T in a real-world setting, clinical characteristics, treatment patterns, and outcomes provide insights into the use and effectiveness of C/T. Disclosures Emre Yucel, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) David Paterson, bioMerieux: Grant/Research Support|bioMerieux: Honoraria|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pfizer: Honoraria|Shionogi: Grant/Research Support|Shionogi: Honoraria Florian Thalhammer, MD, MSD: Advisor/Consultant Stefan Kluge, Prof. Dr. med., Merck & Co: Advisor/Consultant|Merck & Co: Board Member Mike Allen, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) Brune Akrich, MD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company) Yanbing Zhou, PhD, Merck: I am a full time Merck Employee and own stocks in the retirement plan provided by Merck.|Merck: Stocks/Bonds (Public Company)

An outbreak of Shiga toxin-producing Escherichia coli serotype O103:H2 associated with unpasteurized soft cheese, England and Wales, 2022.

In July 2022, a genetically linked and geographically dispersed cluster of 12 cases of Shiga toxin-producing Escherichia coli (STEC) O103:H2 was detected by the UK Health Security Agency using whole genome sequencing. Review of food history questionnaires identified cheese (particularly an unpasteurized brie-style cheese) and mixed salad leaves as potential vehicles. A case-control study was conducted to investigate exposure to these products. Case food history information was collected by telephone. Controls were recruited using a market research panel and self-completed an online questionnaire. Univariable and multivariable analyses were undertaken using Firth Logistic Regression. Eleven cases and 24 controls were included in the analysis. Consumption of the brie-style cheese of interest was associated with illness (OR 57.5, 95% confidence interval: 3.10-1,060). Concurrently, the production of the brie-style cheese was investigated. Microbiological sample results for the cheese products and implicated dairy herd did not identify the outbreak strain, but did identify the presence of stx genes and STEC, respectively. Together, epidemiological, microbiological, and environmental investigations provided evidence that the brie-style cheese was the vehicle for this outbreak. Production of unpasteurized dairy products was suspended by the business operator, and a review of practices was performed.

MpactR: an R adaptation of the metabolomics peak analysis computational tool (MPACT) for use in reproducible data analysis pipelines.

mpactR automates pre-processing of liquid chromatography-tandem mass spectrometry (LC-MS/MS) data from microbiological samples to correct mispicked peaks, resolve inter-sample variation in abundance across technical replicates, account for in-source ion fragmentation, and remove background noise to yield high-quality mass spectrometry features. The package is available through CRAN and GitHub.

The Swab, the Drip, or the Meat? Comparison of Microbiological Sampling Methods in Vacuum-Packed Raw Beef.

Historically, there has been a concern for the detection and enumeration of microorganisms in foods, and numerous methods have been developed to determine their microbiological conditions. The present study aimed to compare the numbers of microbes recovered with three sampling methods: drip, excision, and swabbing in vacuum-packed beef. The sampling methods were evaluated in terms of the viable numbers of Enterobacteriaceae, lactic acid bacteria (LAB), Brochrothrix thermosphacta, Salmonella spp., and yeasts and moulds (Y&M). The numbers of B. thermosphacta, Salmonella spp., Enterobacteriaceae, LAB, and M&Y recovered with the drip method were significantly higher (p < 0.05) than those from the other two methods. Regarding excision and swabbing, the recovery of B. thermosphacta and Enterobacteriaceae was higher (p < 0.05) with the excision method than swabbing, while there were no statistical differences (p > 0.05) between both methods for Salmonella spp., LAB, and Y&M. In conclusion, the drip method can recover up to two logarithms more than the other techniques in vacuum-packed meat; hence, it should be considered when designing and implementing sampling systems for the meat industry.

The Role of Bronchoalveolar Lavage in Therapeutic Antimicrobial Choices for Hematologic Patients with Pulmonary Infiltrates.

Background and Objectives: Lower respiratory tract infections are particularly frequent in hematological patients; their early diagnosis and the timely start of targeted therapy are essential. Bronchoalveolar lavage (BAL) can provide a microbiological sample from the lower airways in a minimally invasive way. This study aimed to determine the diagnostic yield of BAL in hematological patients for microbiological purposes and its influence on modifying the therapeutic strategy. Material and Methods: This multicenter, retrospective, observational study included data from 193 consecutive patients from two centers from January 2020 to October 2022. The patients underwent a bronchoscopy with BAL in cases of pulmonary infiltrates suspicious of pulmonary infection. The demographic data, presenting symptoms, level of immunosuppression, chest CT changes, BAL sampling results, and antimicrobiological drug administration were analyzed. Results: Of the 193 procedures, 143 (74.1%) were performed on hospitalized patients, while 50 were performed on outpatients. In 53.9% of the cases, the BAL isolated at least one germ; in particular, if the procedure was carried out within 72 h of presenting symptoms, the probability of isolating the germ increased significantly (74.3%, p = 0.04). Among the isolated germs, 59.4% were viruses, 28.6% were bacteria, and 12% were fungi. The patients with higher immunosuppression and the febrile ones underwent BAL earlier than the patients with mild immunosuppression (p = 0.01) and those with other presenting symptoms (p = 0.0001). BAL positivity led to a change in empirical antimicrobial therapy in 79 out of 104 cases (77% vs. 36.3%; p < 0.001); these data were also confirmed among the hospitalized patients (81% vs. 44%; p < 0.001). The isolation of a pathogen through BAL and the degree of patient immunosuppression negatively influenced patient survival (p < 0.05 and p < 0.01, respectively). Conclusions: BAL is confirmed as a valid approach for evaluating pulmonary infiltrates in hematological patients, given the excellent clinical impact and high diagnostic yield, mainly if performed early after symptom presentation. However, ongoing antimicrobial treatments at the time of BAL may have potentially affected the diagnostic yield of the procedure.

Microbiological quality of the air in the area of influence of the former wastewater treatment plant in Cajamarca, Peru

It has been determined that there is air pollution within wastewater treatment plants and their surrounding areas. This impacts the health of nearby populations. Therefore, this research aimed to evaluate the air’s microbiological quality in the area of influence of the former Wastewater Treatment Plant (WWTP) in the city of Cajamarca. Microbiological air sampling was conducted during the rainy and dry seasons using the RCS Standard Hycon air sampler, planting on tryptic soy agar medium to determine the total count of all microorganisms, bacteria, and fungi separately. OSHA (Occupational Safety and Health Administration), PN-89/Z-04111/02, and PN-89/Z-04111/03 were the standards used to determine the air quality of the study area since Peru currently does not have such regulation standards. The highest values obtained were 4560 CFU/m³ and 4360 CFU/m³ during the dry season. Sixteen concentrations of the total microorganism count exceeded the limits established by OSHA standards, and ten concentrations of bacteria exceeded the Polish standard PN-89/Z-04111/02. Although the concentrations of fungi were high, they did not exceed any reference limits. We determined a positive correlation between the concentration of microorganisms and the relative humidity, with a maximum of 85.67% humidity during the dry season. Additionally, a negative correlation with wind speed was found, with values ranging from 0.37 m/s to 2.58 m/s during the dry season and from 0.37 m/s to 1.87 m/s during the rainy season. Genera of public health importance such as Staphylococcus and Penicillium were identified. Finally, a survey was conducted among the nearby population to assess the impact on public health. And, it was established that the health impact on the surrounding populations is mainly low.

Microbial Contamination of Nebulizers in Patients With Cystic Fibrosis.

Objective: Nebulizer contamination has potential harmful effects on the respiratory system. The aim was to investigate the contamination profile of the nebulizers in cystic fibrosis patients and evaluate the relationship between hygiene practices and microbial contamination. Materials and Methods: Microbiological swab samples were taken from 3 different locations of the nebulizers of 102 patients. A questionnaire regarding nebulizer hygiene practices was applied to participants. Results: Contamination rate was 40.2%, while chambers were the most contaminated area. The bacterial contamination rate was 37.3%, with gram-negative bacterial growth being predominant. The organisms identified were mostly environmental or floral. Only 3 of the patients were performing the whole steps correctly. This number was not sufficient to assess the relationship between nebulizer cleaning and disinfection practices and microbial growth from nebulizers. When the relationship between nebulizer cleaning/disinfection frequencies, methods, and storage locations was evaluated separately with microbial growth from nebulizers, no statistically significant relationship was found for all (P > .05 for all). Conclusion: The nebulizer contamination rate with pathogenic microorganisms is low in the present study. Regular educational interventions regarding nebulizer hygiene practices should be implemented in all Cystic Fibrosis Centers.

Effect of ozone oil and non-surgical periodontal treatment in patients with type 2 diabetes. In-vivo and in-vitro studies with fibroblasts and Candida albicans.

To evaluate the clinical effectiveness of ozonated sunflower oil (Oz) as an adjunctive of non-surgical periodontal therapy in patients with type 2 diabetes mellitus (DM2), on fibroblast cell viability and migration and the effectiveness of Oz on a Candida albicans (C. albicans) culture. In total, 32 sites in 16 DM2 with moderate to advanced periodontal disease with periodontal pocket depths ≥5mm were selected. The treatments were divided into two groups: control, saline solution (SS) as an adjunctive of scaling and root planing (SRP+SS), and test, Oz as an adjunctive of SRP (SRP+Oz). Hematological [fasting glucose level (FGL) and hemoglobin A1c (HbA1c)] and microbiological samples were collected from the participants at baseline and three months after periodontal treatment and the microbiological samples were analyzed by PCR. C. albicans was previously tested by the agar diffusion test. The effect of Oz was tested on cell viability and fibroblast migration. The groups showed no statistically significant differences (paired t-test-p>0.05) regarding hematological parameters, FGL (median - baseline 171.41, 3 months 164mg/dL), and HbA1c (baseline 8%, 3 months 7.5%) (Kruskal-Wallis One-Way Nonparametric-p>0.05) after periodontal therapy. The groups showed statistical differences for periodontal parameters between baseline and three months (paired t-test-p<0.05). PCR analysis showed a reduction in the percentage of C. albicans in the SRP+Oz group after three months (McNemar's test-p=0.002). Cell viability was lower in the high glucose Dulbecco's modified Eagle's medium (4500 mg/L) than in low glucose (1000 mg/L) (RM-ANOVA-p<0.0001). The wound healing test showed reduced fibroblast migration (one-way ANOVA with Dunnett's post-test-p<0.01). Oz showed high C. albicans antifungal inhibition (Kruskal-Wallis test-p=0.0001). SRP+Oz effectively reduced C. albicans in-vitro and in-vivo but showed no clinical improvements compared to the control. Cell viability and wound healing of fibroblasts showed no improvements.

Evaluation of Candida SPP involvement in women ingesting contraceptives according to the latest classification

Introduction: The study evaluated the relationship between contraceptive use and the presence of *Candida* species in the periodontal microbiome of women. *Candida albicans* was identified as the most common species, although others such as *C. parapsilosis* and *C. tropicalis* were also detected. These yeasts showed a higher prevalence in inflammatory conditions and in advanced stages of periodontal disease. In addition, the influence of female hormones and contraceptives in the alteration of the periodontal microenvironment, favoring the growth of opportunistic species, was considered. Methods: A cross-sectional study was carried out in 100 women, divided into two groups: contraceptive users (n=50) and non-users (n=50). Microbiological samples were collected from various oral surfaces using culture techniques, chromogenic methods and PCR. Participants included immunocompetent women with various periodontal conditions, excluding those with systemic diseases, recent antimicrobial use or smoking habits. Results: Eighty-two *Candida* isolates were identified, with *C. albicans* (34) and *C. parapsilosis* (16) standing out. There were no significant differences in *Candida* colonization between healthy women and women with gingivitis, regardless of contraceptive use. However, in advanced stages of periodontitis, the prevalence of *Candida* was significantly increased in contraceptive users. Conclusions: Contraceptive use did not significantly influence *Candida* colonization in healthy or gingivitis women, but it did in advanced stages of periodontitis. These findings highlight the importance of monitoring periodontal microbiota in women with hormonal changes or hormonal treatments, considering the potential impact of *Candida* as a reservoir of opportunistic infections.

POWDERED FOODSTUFFS INTENDED FOR CHILD FEEDING IN UNDERDEVELOPED COUNTRIES: RISKS OF CONTAMINATION BY SALMONELLA AND ESCHERICHIA

Introduction: Powdered infant milk play a crucial role in infant nutrition when breastfeeding is not available. However, both dairy companies and consumers encounter challenges related to the physicochemical stability, as well as the microbiological quality throughout storage/ distribution. Objective: Study aimed to evaluate microbiological quality and physicochemical stability of eleven imported first-age milk samples from various brands, collected in Algiers city, during spring season. Methods: Samples stability will be assessed by various physicochemical tests (density, pH, titratable acidity, viscosity, protein and lactose levels, etc). Microbiological quality will be explored by research involving colony forming units (CFU) counting on conventional selective culture media, the evaluation of the pathogenic floras/species. Salmonella Enumeration, in addition to conventional method, on three differential selective broths. Results &amp; discussion: Chemical tests indicated that samples remained stable, with the following mean values: Density (1.024), pH (6.655), Acidity (17.628), Viscosity (2.574), Conductivity (1805.72 µS/cm), Total Dissolved Solids (TDS) (85 mg/L), Protein Content (1.66 g/100ml of milk), and Lactose Content (1.5509 g/100ml of milk). Microbiological analysis, apart from absence of Staphylococcus, Cronobacter, revealed following results: yeasts and molds were present in 36.36 % (4/11) of samples, total bacterial count exceeded standards in 27.27 % (3/11) of samples, total coliforms were observed in 9.09 % (2/11) of samples, total fecal coliforms were detected in 9.09 % (1/11) of samples, Escherichia coli was present in 9.09 % (1/11) and D-Streptococcus was found in 18.18 % (2/11) of samples. Research Implications: The entire set samples demonstrated chemical stability throughout storage and distribution, with no packaging or labeling defects noted. However, microbiological quality sample’s fell below local/international standards. In light of these findings, further investigation is warranted through expanded sampling approach, targeting additional PIF brands, conducting a wider array of physicochemical and toxicological tests, and examining a wider of bacterial flora/species.

A comparison of postoperative microbiological and histological test results with the indication for revision as listed at the time of surgery in the National Joint Registry: a single-centre cohort study of metal-on-metal total hip replacement and hip resurfacing revision procedures.

Surgeons allocate an indication(s) for revision surgery on NJR Minimum Data Set forms in the immediate perioperative period, when results from intraoperative histology and microbiology samples are not available. We evaluated to what extent the postoperative diagnostics obtained for patients undergoing metal-on-metal hip arthroplasty (MoMHA) revision surgery align with the indication for revision listed in the NJR. NJR data for MoMHA revision patients (2004-2015) at a single centre were linked to hospital records of microbiology and histology testing for prosthetic joint infection (PJI) and adverse reaction to metal debris (ARMD). The Musculoskeletal Infection Society and Mirra classifications were used as "gold standards' to classify PJI and ARMD respectively and to assess the diagnostic accuracy of the clinician selected revision indication recorded on MDS forms. Of 301 cases, 5.6% (n = 17) and 3.7% (n = 11) were revised for PJI and ARMD respectively. In a further 6.6% (n = 20, PJI) and 15.6% (n = 47, ARMD) the indication for revision selected at the time of surgery did not corroborate with the test results from intraoperative samples. Diagnostic accuracy analysis revealed sensitivity and specificity of indication for surgery at the time of revision for PJI of 35.5% (95% CI, 19.2-54.6) and 97.8% (CI, 54.6-95.2) respectively, and for ARMD of 7.41% (CI, 2.06-17.9) and 97.2% (CI, 94.3-98.9) respectively. We observed that the results of histology and microbiology analyses of intraoperative samples may provide evidence to support alternative diagnoses in 20% of cases. This indicates a need for a change in the work-up of these cases to allow a more accurate prediction of the indication for revision. Alternatively, if there was evidence of a difference in outcome for patients where the indication may be changed when such data becomes available, the feasibility of a facility to add additional information from samples taken intraoperatively when it becomes available should be explored.

A ten-year retrospective analysis of risk factors and comorbidities prevalence in a group of septic arthritis patients.

The aim of this study was the evaluation of a group of patients treated at the Department of Orthopaedics and Traumatology of Locomotory Apparatus at Luis Pasteur University Hospital in Košice for septic arthritis in relation to risk factors and chronic diseases and its microbial aetiologic profile. We conducted a retrospective study of patients including all episodes of septic arthritis from March 2013 to August 2022. The occurrence of chronic diseases, risk factors and its microbiological profile were investigated. A total of 141 patients were included: 92 (65%) males and 49 (35%) females, the mean age of patients was 58.1 years. A continued decrease in cases was recorded during the period of COVID-19 pandemic and the post-pandemic years. The largest group of our cohort represented septic arthritis of the knee (87 cases, 61.7%), followed by hip and shoulder arthritis - 17 (12.1%) and 14 (9.9%) cases, respectively. Gram positive aetiologic flora represented 87.5% of all pathogens isolated and antibiotics were administered to 46 (32.6%) patients before microbiological culture samples were obtained. The dominant chronic disease was diabetes mellitus with 42 (29.8%) cases and degenerative joint disease affecting the joint was verified in 86 (61%) patients. Dental foci in 28 (19.9%) cases and skin infections in 17 (12.1%) cases were the most numerous groups of risk factors with predominant distribution for cases without previous intervention in the affected joint leading to infection. The distribution of joint involvement and microbial agents was similar to other literature without affecting negative culture results by prior administration of antibiotics. Representation of chronic diseases and risk factors was comparable to the work of other authors. Notable was the continued decline in total number of cases in post-pandemic years of COVID-19 pandemic. What was interesting was the number of confirmed cases of distant focal infection distributed mainly in the group of patients without a history of any previous intervention on the joint before the infection. There is a lack of literature on distant silent infection as a risk factor.

Reverse endothelial scraping technique (REST) for an infectious corneal endothelial plaque

A male patient in his 20s, suffering from a persistent, infection-related corneal endothelial plaque (EP) was urgently referred to our tertiary medical centre for therapeutic penetrating keratoplasty (TPK). Over the preceding month, he had been undergoing treatment with both topical and oral antifungal medications due to clinical suspicion of fungal keratitis. At our centre, an endothelial scraping was performed using a reverse Sinskey hook to obtain samples for microbiology and revealed septate branching fungal hyphae. After targeted therapy with intracameral and intrastromal voriconazole injections, the EP healed with scarring and a final visual acuity of 20/30 was achieved. This highlights efficacy of the reverse endothelial scraping technique (REST) in obtaining microbiological samples from corneal EPs, facilitating targeted medical treatment and averting the need for invasive procedures like penetrating keratoplasty in young patients.